package net.jerryfu.decodeAndEncode;/*
 * Copyright 2015-2102 RonCoo(http://www.roncoo.com) Group.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.KeyGenerator;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import Decoder.BASE64Decoder;
import Decoder.BASE64Encoder;

/**
 * AES对称加密和解密
 * @author jerryfu
 *
 */

public class AesUtil {

	private static final Logger LOG = LoggerFactory.getLogger(AesUtil.class);

	public static String key = "R23Con098q7@5";

	/*
	 * 加密 1.构造密钥生成器 2.根据ecnodeRules规则初始化密钥生成器 3.产生密钥 4.创建和初始化密码器 5.内容加密 6.返回字符串
	 */
	public static String AESEncode(String encodeRules, String content) {
		try {
			// 1.构造密钥生成器，指定为AES算法,不区分大小写
			KeyGenerator keygen = KeyGenerator.getInstance("AES");
			// 2.根据ecnodeRules规则初始化密钥生成器
			// 生成一个128位的随机源,根据传入的字节数组
			SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
			random.setSeed(encodeRules.getBytes());
			keygen.init(128, random);
			// 3.产生原始对称密钥
			SecretKey original_key = keygen.generateKey();
			// 4.获得原始对称密钥的字节数组
			byte[] raw = original_key.getEncoded();
			// 5.根据字节数组生成AES密钥
			SecretKey key = new SecretKeySpec(raw, "AES");
			// 6.根据指定算法AES自成密码器
			Cipher cipher = Cipher.getInstance("AES");
			// 7.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密解密(Decrypt_mode)操作，第二个参数为使用的KEY
			cipher.init(Cipher.ENCRYPT_MODE, key);
			// 8.获取加密内容的字节数组(这里要设置为utf-8)不然内容中如果有中文和英文混合中文就会解密为乱码
			byte[] byte_encode = content.getBytes("utf-8");
			// 9.根据密码器的初始化方式--加密：将数据加密
			byte[] byte_AES = cipher.doFinal(byte_encode);
			// 10.将加密后的数据转换为字符串
			// 这里用Base64Encoder中会找不到包
			// 解决办法：
			// 在项目的Build path中先移除JRE System Library，再添加库JRE System
			// Library，重新编译后就一切正常了。
			String AES_encode = new String(new BASE64Encoder().encode(byte_AES));
			// 11.将字符串返回
			return AES_encode;
		} catch (NoSuchAlgorithmException e) {
			LOG.error("NoSuchAlgorithmException:", e);
		} catch (NoSuchPaddingException e) {
			LOG.error("NoSuchPaddingException:", e);
		} catch (InvalidKeyException e) {
			LOG.error("InvalidKeyException:", e);
		} catch (IllegalBlockSizeException e) {
			LOG.error("IllegalBlockSizeException:", e);
		} catch (BadPaddingException e) {
			LOG.error("BadPaddingException:", e);
		} catch (UnsupportedEncodingException e) {
			LOG.error("UnsupportedEncodingException:", e);
		}

		return null;
	}

	/*
	 * 解密 解密过程： 1.同加密1-4步 2.将加密后的字符串反纺成byte[]数组 3.将加密内容解密
	 */
	public static String AESDncode(String encodeRules, String content) {
		try {
			// 1.构造密钥生成器，指定为AES算法,不区分大小写
			KeyGenerator keygen = KeyGenerator.getInstance("AES");
			// 2.根据ecnodeRules规则初始化密钥生成器
			// 生成一个128位的随机源,根据传入的字节数组
			SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
			random.setSeed(encodeRules.getBytes());
			keygen.init(128, random);
			// 3.产生原始对称密钥
			SecretKey original_key = keygen.generateKey();
			// 4.获得原始对称密钥的字节数组
			byte[] raw = original_key.getEncoded();
			// 5.根据字节数组生成AES密钥
			SecretKey key = new SecretKeySpec(raw, "AES");
			// 6.根据指定算法AES自成密码器
			Cipher cipher = Cipher.getInstance("AES");
			// 7.初始化密码器，第一个参数为加密(Encrypt_mode)或者解密(Decrypt_mode)操作，第二个参数为使用的KEY
			cipher.init(Cipher.DECRYPT_MODE, key);
			// 8.将加密并编码后的内容解码成字节数组
			byte[] byte_content = new BASE64Decoder().decodeBuffer(content);
			/*
			 * 解密
			 */
			byte[] byte_decode = cipher.doFinal(byte_content);
			String AES_decode = new String(byte_decode, "utf-8");
			return AES_decode;
		} catch (NoSuchAlgorithmException e) {
			LOG.error("NoSuchAlgorithmException:", e);
		} catch (NoSuchPaddingException e) {
			LOG.error("NoSuchPaddingException:", e);
		} catch (InvalidKeyException e) {
			LOG.error("InvalidKeyException:", e);
		} catch (IOException e) {
			LOG.error("IOException:", e);
		} catch (IllegalBlockSizeException e) {
			LOG.error("IllegalBlockSizeException:", e);
		} catch (BadPaddingException e) {
			LOG.error("BadPaddingException:", e);
		}

		return null;
	}

	public static void main(String[] args) {
		String source = "签名原文是:为二位二位vfwwr23r32434为二位二位vfwwr23r32434为二位二位vfwwr23r32434为二位二位vfwwr23r32434";
		String secret = AESEncode(key, source);
		System.out.println("加密后结果:" + secret);
		System.out.println("解密后结果:" + AESDncode(key, secret));
	}

}